Once again proving its commitment to "Power by Design," the new RHS Pro Torker Vortec Iron Performance cylinder heads deliver superior flow characteristics over all other previously available iron small-block Chevrolet heads. In comparison to the popular GM 906 casting, the RHS Pro Torker Vortec cylinder heads deliver 27 more cfm at 0.500-inch lift. Constructed from high quality cast-iron, these heads are perfect for racing classes where iron heads (with standard 2.02-inch intake and 1.600-inch exhaust valve sizing) are required. Featuring dual pattern (four and six bolt) intake compatibility, these heads work with virtually any intake manifold (including early style) rather than being restricted to Vortec-style components, which has been a limiting factor in the past.

The new Pro Action cylinder heads use advanced airflow and cooling technology to deliver the most "out of the box" power and torque available, claims RHS. A manufacturing process labeled Clean Cast Technology ensures that its products meet strict tolerances and achieve superior final workmanship in order to eliminate the need for extensive after-purchase porting. As an added benefit, the refined RHS water jacket design flows much better than the competition, delivering improved heat dissipation and yielding more consistent and reliable horsepower.

Dart has developed more efficient port designs with improved velocity and flow capabilities, and the results are the Iron Eagle Platinum cylinder heads. The combustion chamber of these heads has been redesigned, and the casting walls made cleaner, for greater breathing characteristics and more controllable combustion. Also featured are hardened exhaust seats for better durability with unleaded fuel, and a 5-angle competition valve job on the intake, with a full radius on the exhaust valve. These heads also accept most stock bolt-on components. The result of three decades of cylinder head development, Iron Eagle heads incorporate features that were previously available only in expensive aluminum cylinder heads. Dart designed the Iron Eagle heads for street performance, bracket racing, oval track competition, and high-performance marine use. five different intake ports are offered: 165cc, 180cc, 200cc, 215cc, and 230cc, that cover virtually every engine application. Dart Iron Eagle heads have standard features you don't get in other factory and aftermarket cast-iron cylinder heads. Long-wearing bronze valve guides (except S/S), multi-angle intake valve seats, and hardened and radiused exhaust seats are standard.